Two Mistakes in Flap Discs Choosing

Flap disc is usually used in angular grinder. Owing to its good grinding ability, high efficiency, low noise and good safety, flap disc is widely applied in rust removal, paint removal and grinding welding of metal or non-metallic surfaces. So to speak, flap disc is a star in metal polishing. However, it is easy to make mistakes when choosing flap discs.  

Mistake One: Pay too much attention on the form of flap disc

Flap discs have two kinds of shapes, curved type and flat type. As its name implies, flat flap disc has a smooth buffed surface, while curved flap disc has an upward curved grinding surface. Judging from appearance, the difference between those two types flap discs is obvious. Therefore, someone hold that because all vanes in curved flap disc can touch the surface of work pieces, the cutting speed and surface effect of curved flap discs would be better than that of flat flap discs. In fact, with the wear of vanes, some curves will show on flat flap discs, and there is seldom difference on grinding effect between flat flap discs or curved flap discs. As a result, when buying flap discs, it is reasonable to choose flat flap disc or curved flap disc based on your personal preference. 

Mistake Two: The more vanes, the better 

Compared with ordinary flap disc, some flap discs produced by certain abrasives manufacturers have more vanes in unit area. In their propaganda, that special flap discs with more vanes are often labeled as "High density ","long life " and "the giant in grinding". But that is just means of promotion of abrasives manufacturers. Actually, high density of vanes in flap discs means high producing cost. However, because the number of vanes increases, the angle of blade inserting is accordingly improved, which improved grinding efficiency and result in more rough surface after polishing. With regard to service life of flap disc, generally speaking it is true that the more vanes, the longer that flap disc can be used. But the vane number is not the decisive factor for flap disc's lifespan. 

The backing pad of flap discs is often made from three kinds of materials, namely ordinary cotton, mixed material of polyester and cotton, as well as pure polyester. Among them, the most hard is the pure polyester, while ordinary cotton is the most vulnerable to wear and tear. In order to expand service life of flap discs and make full use of all vanes in them, it is essential to choose the most suitable back pad material in accordance with the hardness of materials to be polished, grinding pressure and grinding quantity. Choosing flap discs with polyester as back pad in low grinding pressure will lead to ore sand covered by metal debris after blunt; while choosing flap disc with ordinary cotton back pad in large grinding pressure would wear vanes too fast and shorten service life of flap discs.